日常生活中我们经常在不同的媒体见到“资产泡沫”这个词，但很少人能够真正表达其具体定义或涵义。一般而言，房地产泡沫是指房地产价格偏离了基本价值的部份。大多数量度泡沫的方法都是以相关数据的水平值来计算(例如收益还原法及指标法)，而忽略数据的增长率。本文则以房地产价格增长率与修正了的资本边际收益率的偏离，去量度房地产泡沫。由于这方法需要计算的变数较少，故此比较简单直接。我们亦将这个方法运用于上世纪80年代后期的日本地价、及上世纪80年代至近年的香港住宅楼价分析上，发现两地的房地产泡沫，都很容易便能以简单的图表显示出来。<br/>We always come across the term “real-estate bubble” in various media in our daily life, however, not many of us can give a proper definition or explain the meaning of it. Basically, real-estate bubble is the deviation of the market value of a real-estate from its fundamental value. Most of the measurements of bub- bles are using level values of relevant data (e.g. Return-discounting model and index model), rather than us- ing the growth rates. This paper uses the deviation between the growth rate of real-estate price and the “re- fined” marginal return of capital to measure bubbles. Since this method involves a smaller number of relevant variables, it is more simple and direct. Applications have been made to the analyses of land price of Japanand property-price ofHong Kong, since 1980s, and real-estate bubbles of the two economies can be shown clearly in simple graphs.